Moisture determining apparatus



R. T. BELL 2,280,617 MOISTURE DETERMINING APPARQTUE Fil ed Dec. 18. 19392 Sheets-Sheet l x INVENTORI RIF-BELL FIGJ Q BY a%m V5 ATTORNE SPatented Apr. 21, 194-2 TES FFECE 3 Claims.

This invention relates to apparatus for determining the bulk specificgravities of saturated surface dry material and the moisture content ofany known quantity of moist material such as sand, gravel, coal, pulp,ore concentrates, grain, etc.

According to one feature of this invention, the moisture content of asample of moist material is determined by a method which consists inplacing in a test Vessel a quantity of moist material of a known weight,adding a given volume or known weight of water to the moist material sothat the combined volume of the two will cause the water to reach acertain level in the gauge glass in the neck of the test vessel.

Another feature of my invention is to provide an adjustable apparatusfor determining the moisture content of any known quantity of moistmaterial.

Other features of this invention will be more readily understood fromthe following description taken in connection with the accompanyingdrawings, in which- Fig 1 is a front sectional view of the apparatusembodying my invention.

Fig. 2 is a fragmentary front elevational view of the apparatus shown inFig. 1, this view show- 7 Fig. 6 is a plan view of the apparatusdisclosed in Fig. 1.

As illustrated in the accompanying drawings, 5 designates a receptaclehaving lug portions 5 on either side at the top. Clamping bolts 1,provided with thumb screws 8, are hingedly mounted in lugs 6 forsecuring lid 9 to the top of the receptacle 5. A circular groove I0 isprovided in the top of the receptacle 5 and a washer II is mountedtherein which seals against the face of the lid 9 adjacent thereceptacle 5. The lid 9 is provided with a circular neck portion I2which is cut away at the front and rear as indicated at I3 and I4. Theneck portion l2, therefore, forms two side walls which support a gaugeglass I5. The gauge glass 55 rests on a ledge I5 within an opening IT inthe lid 9 and is preferably cemented to the ledge IS.

The right side of the neck I2 is provided with a calibrated plate I8which carries specific gravity index markings. The plate I8 may befastened at any portion throughout the length of the front face of theneck I2 when the vessel is calibrated. Over the neck 12 is placed aslide or cursor I9 which is adjustably positioned on the neck I2 by setscrew 26. The cursor I9 is provided with circular bands at top andbottom, the side walls defining front and rear vision openingscorresponding with the openings I3 and Id of neck l2, and slides overthe plate l8. A moisture percentage indexed plate 2I is secured to theleft hand front face of the cursor 99 between the top and bottomcircular bands.

As shown in Fig. 4, the moisture percentage indexed plate 2| may beprovided with an extension plate 25 which is folded as indicated at 25,the extension plate 26 being curved to fit around the left hand sidewall of the cursor I9. The plate 2G is provided with specific gravityreadings and a transparent spring clip marker 26 or other suitable meansis slidably mounted on the cursor The method of operation is as follows:First, for bulk specific gravity (saturated surface-dry basis), theflask or test vessel is used as an ordinary specific gravity flask, i.e., a quantityof known weight of saturated surface dry material isplaced in the lower portion of the test vessel 5;,

the cover or lid 9 and neck I2 which are in one piece is then placed inposition and the thumb screws 8 tightened to prevent leakage. A knownweight or volume of water is then poured into' Bulk specific gravitysaturated surface dry basis The bulk specific gravity, on the weight ofsaturated surface dry aggregate, shall be calculated from the followingformula, I

Bulk specific gravity= E where B=weight in grams of surface drysaturated sam ple in air Y C=weight in grams of surface dry saturatedsample in water. 7

Cubic inches X C where A=weight of water B=specific gravity l=l cubicfoot of water weighing 62.415 lbs, at 3 centigrade C=1728 cubic inchesin 1 cubic foot.

Substituting values for a four pound weight of water,

i X1728=110.742 cubic inches, the volume of 4 lbs. of water.

For computing the volume for materials of various specific gravities thefollowing formula is used,

Cubic inches== where D=110.'742 E=specific gravity.

Substituting values for specific gravity 2.0

=55.371 cubic inches the volume of a 4 lb. sample of material with aspecific gravity of 2.0.

weight containing various percentages of moisture, the following formulais used:

Aggregate X D cubic inches Water g-X D cubic inches where A:the amountof dry aggregate in sample B=the amount of water in sample C=62.415 lbs.the weight of 1 cubic ft. of water D=1728 cubic inches E=the specificgravity of the material under test.

Substituting figures Cubic Inches 3. 6364 Material X 1728 50. 337

0.3636 Water 1728 10. 067

Total 60. 404 Add two lbs. water 55. 371

Total in test vessel ll5. 775

In the present instance the specific gravity index plate I8 is showngraduated in terms of The range of specific gravities required are com-Cu. ins. 4 lb. sample of material specific gravity 2.0 55.371 2 lb.water added 55.371

In test vessel 110.742

To ascertain the amount of water present in moist sand or other materialof known bulk specific gravity, a sample of definite weight is placed inthe lower portion of the test vessel, and a known weight or volume ofwater is added thereto. The cursor I9 is then adjusted until the zeromark on plate 2| coincides with the graduation mark on plate l8representing the specific gravity of such material when free ofmoisture. The height to which the water rises in tube I5 is then readoff on plate 2| and represents that difierence between the bulk of thedry material and the moist material which is due to the amount ofmoisture present in the moist material, the plate 2| being graduated interms of the percentage of moisture in the material.

Having established the total volumes for the various bulk specificgravities incidental to the gravel, sand and other concrete aggregates,i. e. from 2.5 to 2.9 to arrive at the total volume of dry aggregate andwater in a sample of a known specific gravities ranging between 2.5 and2.9 since, in actual practice, few, if any, concrete aggregates havespecific gravities below or above these figures. The moisture percentageindex plate 2| is graduated in terms of moisture percentages rangingfrom 1 to 12 percent.

If greater exactitude is required use is made of the auxiliary specificgravity index scale carried by the extension plate 24. The gauge glassI5 is correct for specific gravity reading of 2.64 which is the averagespecific gravity for commercial purposes. However, if the specificgravity of the substance should be, for example, 3.0 and the moisturecontent was indicated as 10% by readcontent would be 9.4% at S. G. 3.

ing along the marker 26 to the line indicated at a specific gravity of3, the exact moisture percentage could be determined. For instance,instead of being 10% at S. G. 2.64 the moisture It will readily be seentherefore that exact moisture percentages can be determined for any ofthe specific gravities between 2.6 and 3.0. It is obvious that, theplate 24 may be provided with a much wider range of specific gravityreadings.

Another modification would be to provide separate gauge plates I8 foreach and every specific gravity.

Instead of the openings provided in the side walls of the cursor [9,these side walls may be made transparent.

' Having thus described my invention, what I claim is:

1. Apparatus for determining the bulk specific gravities of saturatedsurface dry materials and the moisture content of moist materials ofknown specific gravity comprising a receptacle provided with a coverhaving a tubular member extending upwardly therefrom, said tubularmember J surrounding an opening formed in said cover and being providedwith a sight opening, a transparent gauge tube arranged in said tubularmember and communicating with the interior of said receptacle, an indexplate secured to said tubular member at one side of said sight opening,said index plate being graduated in terms of specific gravity, a cursorslidably mounted on said tubular member for movement longitudinallythereof, and a second gauge or index plate carried by said cursor, saidsecond gauge plate being graduated in terms of moisture content.

2. Apparatus for determining the bulk specific gravities of saturatedsurface dry materials and the moisture content of moist materials ofknown specific gravity comprising a receptacle provided with a cover, atransparent gauge tube rising from and rigidly secured to said cover,said tube being in communication with the interior of said receptacle, acalibrated index plate secured in a fixed position and extending along aportion of the gauge tube, said index plate being graduated in terms ofspecific gravity so that, when a quantity of known weight of saturatedsurface dry material is placed in the receptacle along with a knownweight or volume of water, the bulk specific gravity of said materialmay be read directly from said index plate as the function of the heightto which the water rises in the vessel, a cursor slidably adjustablealong the length of the gauge tube and a second index plate fixed totravel with said cursor, said second index plate being graduated interms of moisture content and being calibrated so that when a measuredquantity of moist material, whose specific gravity is known or has beenascertained by the use of the first mentioned index plate, is placed inthe vessel along with a known Weight or quantity of water, the moisturecontent of said moist material may be determined by adjusting the cursoruntil the zero mark on the second mentioned index plate coincides withthat graduation mark on the first mentioned plate which represents thespecific gravity of such material when free of moisture, the moisturecontent of said material being then readable on the second index plateat the level to which the water rises in said vessel. 3. Apparatus asset forth in claim 2 including an auxiliary specific gravity index plateattached to said cursor and an auxiliary cursor slidably mounted on saidfirst mentioned cursor to facilitate the reading of said auxiliarygravity index plate, said auxiliary index plate and said auxiliarycursor being used when the approximate specific gravity readings of thefirst mentioned specific gravity index plate are not suflicientlyaccurate.

RICHARD T. BELL.

